JPS5855663A - Air conditioner for room - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a room air conditioner, and more particularly to a room air conditioner equipped with a compressor whose capacity can be controlled and aimed at stabilizing low-load cooling operation.

First, a heat pump type room air conditioner equipped with a capacity controllable compressor will be described as an example of a conventional room air conditioner equipped with a capacity controllable compressor.

Figure 1 is a cycle configuration diagram of a heat pump room air conditioner equipped with a compressor that can control the capacity.
FIG. 3 is a partially enlarged sectional view showing details of the outdoor heat exchanger in the figure and the state of refrigerant flowing inside the outdoor heat exchanger during cooling.

In Fig. 1, 1 is a capacity controllable compressor (hereinafter simply referred to as a compressor), 2 is a four-way valve, 3 is an indoor heat exchanger, and 4
5 is a check valve, 5 is a capillary tube for heating, 6 is an outdoor heat exchanger (details will be described later), 7 is a reverse valve, 8 is a capillary tube for cooling, 9 is outdoor heat exchanger piping (A), 10 is , outdoor heat exchanger piping (B).

The outdoor heat exchanger 6 will be described in detail using FIG. 2. 11 is a tube related to the heat exchanger body, 11a
is provided at the lower part of the tube 11 and is connected to the outdoor heat exchanger piping (A) 9, and 11b is the cooling refrigerant inlet provided at the upper part of the tube 11 and connected to the outdoor heat exchanger piping (B).
) A cooling refrigerant outlet connected to 10 and 12 are fins attached to the tube 11.

The solid line arrows indicate the flow direction of the refrigerant during heating, and the broken line arrows indicate the flow direction during cooling and defrosting.

During heating, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2 and is sent to the indoor heat exchanger 3, where it radiates heat to the indoor air and becomes liquid refrigerant, which passes through the check valve 4. It is sent to the capillary tube 5 for continuous heating. capillary tube 5
The refrigerant whose pressure has been reduced is heated by outside air in the outdoor heat exchanger 6, becomes a gas refrigerant, passes through the four-way valve 2, is sucked into the compressor 1 again, and goes through the cycle.

During cooling, the four-way valve 2 is switched, and the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 is sent to the outdoor heat exchanger 6, radiates heat to the outside air, and condenses to become liquid refrigerant.

This liquid refrigerant is sent to the cooling capillary tube 8 through the check valve 7, is depressurized, and evaporates while cooling the indoor air in the indoor heat exchanger 3, becoming a gas refrigerant, and passing through the four-way valve 2. The air is sucked into the compressor 1 again and goes through the cycle.

During defrosting, the four-way valve 2 is switched from heating operation to the same cycle as during cooling described above.

The flow of refrigerant in the outdoor heat exchanger 6 during cooling.

The following is an explanation using FIG. 2.

In FIG. 2, broken line arrows indicate the flow direction of the refrigerant during cooling, as in FIG.

From the compressor 1 to the four-way valve 2. The high-temperature, high-pressure gas refrigerant sent through the outdoor heat exchanger piping (A) 9 is transferred to the tube 11.
The refrigerant flows into the tube 11 in the inlet direction from the cooling refrigerant inlet 11a located at the bottom of the tube 11, is cooled to a saturation temperature by outdoor air, and begins to condense. Furthermore, while condensing, the already condensed refrigerant is pushed up and flows upward, flows out from the cooling refrigerant outlet 11b in the direction B, and flows into the outdoor heat exchanger pipe (B) 10.

By the way, when a capacity control compressor with a large capacity control range (for example, a rotation speed control compressor) is used as the compressor 1, if the compressor capacity is controlled to a small value during cooling, the amount of refrigerant circulation will be small. If the refrigerant flow rate is also slow, the force to push the condensed liquid refrigerant upward in the tube 11 is lost. For this reason, the condensed liquid refrigerant accumulates in the tube 11 from below, resulting in a refrigerant shortage condition, and at the refrigerant outlet 11b during cooling, outdoor heat exchange is performed in a state where the refrigerant is highly evaporative, that is, there is a large amount of gas. It flows out into the pipe (B) 10 and is sent to the J pipe pipe 8 for cooling. Therefore, the resistance in the cooling capillary tube 8 is large and the amount of refrigerant circulated is extremely reduced, and almost no liquid refrigerant is sent to the indoor heat exchanger 3 and evaporated, making it impossible to obtain a cooling effect. This phenomenon occurs not only when the compressor capacity is reduced during low cooling loads as described above, but also when the outside air temperature is low and the refrigerant easily condenses in the outdoor heat exchanger 6. be.

For this reason, there was a drawback that stable operation with controlled compressor capacity was not possible.

The present invention eliminates the drawbacks of the prior art described above, and when cooling,
The purpose is to provide a room air conditioner that can maintain stable operation by keeping the degree of refrigerant discharged from an outdoor heat exchanger small even when the compressor capacity is controlled to be small or the outside air temperature is low. It is something.

The features of the present invention include at least a capacity controllable compressor;
In a room air conditioner equipped with an indoor heat exchanger and an outdoor heat exchanger, the cooling refrigerant inlet of the outdoor heat exchanger is placed at the top of the heat exchanger body, and the cooling refrigerant outlet is placed at the bottom of the heat exchanger body. Each room has its own air conditioner.

More details are as follows.

In the conventional room air conditioner described above, the cooling refrigerant outlet 11a of the outdoor heat exchanger 6 is provided in the lower part of the tube 11, and the cooling refrigerant outlet 11b is provided in the upper part of the tube 11. Since the flow of refrigerant in the exchanger 6 is the same as during cooling, when defrosting operation is performed, the surface of the frost that has formed will melt, and silk will flow down from the top of the outdoor heat exchanger 6 and accumulate in the bottom. However, by guiding the high-temperature, high-pressure gas refrigerant to the cooling refrigerant 11a provided at the bottom of the outdoor heat exchanger 6, the heat of the gas refrigerant can be used to melt the frost accumulated at the bottom of the outdoor heat exchanger 6. It was for the purpose of Therefore, since the heat of the high-temperature, high-pressure gas refrigerant, which is the highest temperature, is used to melt the frost, there is an advantage that the defrosting time is shorter than in the case otherwise.However, as mentioned above, when cooling, the compressor capacity When controlled to a small value,
Cooling operation has become unstable.

Therefore, in the present invention, the refrigerant inlet for cooling of the outdoor heat exchanger is provided at the upper part of the tube, and the refrigerant outlet for cooling is provided at the lower part of the tube. The refrigerant flows down from the top to the bottom along the flow of the refrigerant, allowing stable operation even when the compressor capacity is reduced. However, in such a configuration, although the defrosting time becomes a little longer, the effect of stably operating the room air conditioner when the compressor capacity is controlled during cooling is much greater. Incidentally, the above-mentioned problem that the spacing between the shafts and the shafts is slightly longer is completely solved in the embodiment shown in FIG. 4, which will be described later.

The present invention will be explained below with reference to Examples.

FIG. 3 shows a room air conditioner according to an embodiment of the present invention.
FIG. 2 is a partially enlarged sectional view showing details of the outdoor heat exchanger and the state of refrigerant flowing inside the outdoor heat exchanger during cooling (the cycle configuration is the same as FIG. 1).

In FIG. 3, the same parts as in FIG. 2 are denoted by the same numbers. In this outdoor heat exchanger 6A, a cooling refrigerant outlet 11a is provided in the upper part of the tube 11 related to the heat exchanger body, and a cooling refrigerant outlet 11b is provided in the lower part of the tube 11.

With this configuration, during cooling, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger piping (A) 9 and is transferred to the upper part of the tube 11 of the outdoor heat exchanger 6A during cooling. The refrigerant flows into the tube 11 in the direction A from the refrigerant population 11a, is cooled by the cooling air in the lower part, and begins to condense.The refrigerant further flows down toward the cooling refrigerant outlet 11b while condensing. Therefore, at the cooling refrigerant outlet 11b, the refrigerant becomes a supercooled liquid refrigerant or a refrigerant with a low degree of freshness, and flows out to the outdoor heat exchanger pipe (B) 10, and is sent to the cooling capillary tube 8. It will be done.

Therefore, the resistance in the cooling capillary tube 8 does not increase, and a stable refrigerant circulation amount can be obtained.

FIG. 4 is a partially enlarged cross-sectional view showing the details of the outdoor heat exchanger of a room air conditioner according to another embodiment of the present invention and the state of the refrigerant flowing inside it during cooling (the cycle configuration is , the same as in Figure 1).

In this Fig. 4, the same numbers as in Fig. 2 are given, and the parts are the same. This outdoor heat exchanger 6B has one end connected to the cooling refrigerant port 11a of the tube 11 at a brazing portion 14 below the tube 11 related to the heat exchanger main body, and the other end into which a refrigerant is introduced during cooling. A defrosting superheating tube 13 having an inlet 13a is provided. In addition,
12A is the tube 11 and the defrosting superheating tube 13
It is a fin attached to the

With this configuration, during cooling, the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger piping (A) 9 and from the inlet 13a of the defrosting superheating tube 13 of the outdoor heat exchanger 6B. It flows into the defrosting superheating tube 13 in the A direction, is cooled to the saturation temperature by the outside air, begins to condense near the cooling refrigerant population 11a, enters the saturation region in the tube 11, condenses, and flows downward along the flow. flows down to Then, the refrigerant at the refrigerant outlet 11b during cooling becomes a supercooled drip refrigerant or a refrigerant with a low degree of dryness, as in the above embodiment, and is transferred to the outdoor heat exchanger pipe (B) 1o.
and is sent to the cooling capillary tube 8. Therefore, a stable amount of refrigerant circulation can be obtained.

Furthermore, when defrosting operation is performed, the refrigerant flow is similar to that during cooling, so that the frost that flows down from the upper part of the outdoor heat exchanger 6B to the lower part due to defrosting is melted. Since the heat of a certain high-temperature, high-pressure gas refrigerant can be utilized, the defrosting time is no different from that of the conventional outdoor heat exchanger according to FIG. 2.

In this embodiment, the overheating tube 13 for defrosting is connected to the tube 11 at the brazing portion 14, but the tube 11 and the overheating tube 13 for defrosting may be formed integrally.

Furthermore, although each of the above embodiments describes a heat pump type room air conditioner, the present invention is not limited to a heat pump type room air conditioner, but can be applied to a cooling-only room air conditioner with a compressor whose capacity can be controlled, and others. be.

According to each of the embodiments described above, even when the compressor capacity is controlled to be small during cooling and the outside air temperature is low and the refrigerant is likely to condense, the liquid refrigerant condensed in the outdoor heat exchanger will Since the refrigerant flows downward along the flow direction, the refrigerant exiting the outdoor heat exchanger can exit as a supercooled liquid refrigerant or in a state with a low degree of freshness. Therefore, the state of the refrigerant in front of the cooling capillary tube is almost liquid, and a cooling effect can be obtained even when the capacity is small.

According to the embodiment shown in FIG. 4, during defrosting, the high-temperature, high-pressure gas refrigerant is made to flow into the defrosting superheating tube disposed below the heat exchanger main body, so that the temperature of the outdoor heat exchanger is Since the heat of the high-temperature, high-pressure gas refrigerant is used to melt the frost that has fallen to the bottom, the time required to melt the frost remains the same as before.

As described in detail above, according to the present invention, in a room air conditioner equipped with at least a capacity-controllable compressor, an indoor heat exchanger, and an outdoor heat exchanger, the refrigerant inlet of the outdoor heat exchanger during cooling is controlled. The refrigerant outlet for cooling is provided at the top of the heat exchanger body, and the refrigerant outlet for cooling is provided at the bottom of the heat exchanger body. It is possible to provide a room air conditioner that can maintain stable operation by keeping the degree of refrigerant discharged from a heat exchanger small.

[Brief explanation of the drawing]

Figure 1 is a cycle configuration diagram of a heat pump room air conditioner equipped with a compressor that can control the capacity. Figure 2 shows the details of the outdoor heat exchanger in Figure 1 and the state of the refrigerant flowing inside it during cooling. FIG. 3 is a partially enlarged cross-sectional view that also shows the details of the outdoor heat exchanger of a room air conditioner according to an embodiment of the present invention, and the state of the refrigerant flowing inside it during cooling. The cross-sectional view, FIG. 4, is a partially enlarged cross-sectional view showing details of the outdoor heat exchanger of a room air conditioner according to another embodiment of the present invention, and the state of the refrigerant flowing inside the air conditioner during cooling. DESCRIPTION OF SYMBOLS 1... Capacity controllable compressor, 3... Indoor heat exchanger, 6A, 6B... Outdoor heat exchanger, 11... Tube, 11a... Refrigerant inlet during cooling, llb... Refrigerant outlet during cooling, 13... Overheating tube for defrosting, 13a...
Inlet of superheated tube for defrosting. $ I eyes, S δ

Claims (1)

[Claims] 1. A room air conditioner equipped with at least a capacity controllable compressor, an indoor heat exchanger, and an outdoor heat exchanger,
A room air conditioner characterized in that a cooling refrigerant inlet of an outdoor heat exchanger is provided at the upper part of the heat exchanger main body, and a cooling refrigerant outlet is provided at the lower part of the heat exchanger main body. 2. A defrosting overheating tube is provided below the outdoor heat exchanger main body, one end of which is connected to the refrigerant inlet for cooling of the heat exchanger main body, and the other end of which has an inlet for introducing refrigerant during cooling. A room air conditioner as described in claim 1.